text: Maddock was born in Bedford Park, a garden suburb of London, and was educated at Latymer Upper School. He won a state scholarship to study chemistry at the Royal College of Science (RCS), then a constituent part of Imperial College London. After his undergraduate education, he continued on to postgraduate studies at RCS under the supervision of inorganic chemist Professor H. J. Emeléus. Those studies related to silicon hydrides, and he was awarded his PhD in 1942.
  During the early years of World War II, his other studies included methods of protection against arsine, which had been proposed as a chemical warfare agent. He also studied the toxicity of volatile compounds of fluorine; which resulted in his suffering an acute case of poisoning. He and Lord Rothschild devised a device based on mercuric chloride which was used by Allied parachutists into France.
  In 1941, he got to know several French nuclear physicists from the Curie Institute in Paris who had escaped the Nazi invasion. He initially worked with them at the Cavendish Laboratory in Cambridge, and later moved with them and others to Ottawa, Canada, where he helped build a heavy water reactor, as part of what was first known as the Tube Alloys Project and later as the Manhattan Project. It was during that time that he spilled Canada's supply of plutonium (about 10 mg) onto a wooden laboratory bench. He pragmatically sawed it into pieces, ashed them, and recovered the plutonium by wet chemistry.
  After the War, he returned to England; was appointed lecturer in the Department of Chemistry at the University of Cambridge, where Emeléus now occupied the chair of inorganic chemistry; and was elected Fellow of St Catharine's College.
  He had a broad range of scientific interests, which included: the chemistry of the actinide elements, in particular plutonium and protactinium; the chemistry associated with nuclear transformation; solvent extraction; radiation of inorganic solids; the chemistry of positronium ions; and Mössbauer spectroscopy, in which he was a pioneer. He was consultant to the International Atomic Energy Agency, and to atomic energy projects in various countries. He published more than 300 scientific papers.